WARNING: The following contains spoilers for One Piece Chapter #1014 by Eiichiro Oda, Stephen Paul and Vanessa Satone, available in English now from Viz Media.
Chapter #1014 of One Piece has the war against Kaido and Big Mom reaching its apex. Luffy has been defeated. Everyone else, meanwhile, is at their limit, with several more characters being cut down after the announcement of Luffy's loss. Right now, there doesn't seem to be any hope that Wano will be freed from Kaido and Big Mom's tyranny.
Luffy is not only unconscious but also sinking to the bottom of the ocean, unable to swim. Even if he were conscious, there wouldn't be anything he could do, either, because Devil Fruit users are unable to swim or use their powers in water. (More specifically, still bodies of water render the users weak and unable to move, while moving water has no effect.) This is why fights can still take place when it's raining. So even if Kaido hadn't knocked him out, he's still currently at risk of drowning.
All hope is not lost, though. There's still a chance that one of the other characters will be able to save Luffy and return him to the battleground. Who that character is is up for speculation, but there are several possibilities. Jinbe might be able to make it, but he has to take out Who's-Who first. There's also the possibility a character that wasn't shown in the chapter could save him, like Hiyori. Fish-men could also be posted around the island just in case such an event were to occur, so it could be that someone not currently fighting saves Luffy. It's even possible he won't make it back before the battle is over.
If that's the case, then who would be the one to defeat Kaido? Many fans believe Zoro is set up to be the one to take him out. If Hiyori doesn't save Luffy, it could be she comes back to help Zoro heal his wounds so that he can face Kaido himself. Sanji says that he's not a doctor, giving Hiyori an opportunity to come in and take care of that problem and help the Straw Hats when they need it most. She's already helped him with an injury once before, which could be foreshadowing that she would return during the battle to once again help Zoro. Right now, Zoro has about 20-30 broken bones and is wrapped up like a mummy, so if he's the one who's going to fight Kaido, he's going to need a lot of help healing.
However, there also appears something important happening with Momonosuke. In the chapter, he begins hearing something while hiding just before the announcement of Luffy's loss is made. Later, he says that they have to tell everyone something, but it's never clarified what that something is, as they are attacked just before he can explain. It could be that Momonosuke is being set up to reveal a secret that could lead to Kaido's defeat. One Piece fans have a nail-biting wait, now, to find out.